[blazee]

I know that it may seem like a purist approach, but I can confirm what Old Master has said in regards to the quality of parts. The Vortec engines are temperamental, and using certain parts insure their reliability. As Old Master mentioned Bosch for example, make great plugs, but they can't be used in a Vortec as they are prone to fouling. Many other spark plugs cause problems as well. I've used Autolite Platinum plugs before with no problems and other times they've caused hesitation, rough idle and lower fuel economy. Aftermarket distributor caps are one of the most common problem causers after a tune up, they simply don't have the same tolerances as the AC Delco caps, causing poor spark transfer which affects performance, and many don't seat as they should allowing moisture to enter the cap causing issues in damp and rainy conditions. For the rotors, I haven't personally seen anyone have trouble with the aftermarket ones, however considering the quality of the caps, I also use AC Delco rotors as well, because the price isn't much different. The wires.... AC Delco makes great wires, however the price is way too high, considering that you can get a set of Autolites with similar performance for 1/3 - 1/4 of the price. For the price, Autolite wires are the best value. You get an excellent electrical connection, more than adequate insulation, and boots that will seal and last a long time. Many of the other aftermarket ones simply don't perform the way they should, and the new cheapies may actually be worse than the ones you are taking off.

Note: The above was in reference to the parts for the vehicles in general, and not a diagnosis of your problem (other than checking the fitment of your cap) or a recommendation to change any parts considering I have no idea what parts/brands that you bought.


As for the spark jumping, any cracks in the boot or the coil will allow the spark to jump. Other than faulty equipment, the connection is the next suspect. Not only do you have to make sure that boot fits snugly all the way down, but also that the terminal snaps into place. As Old Master stated dielectric grease should be applied to all connections before making them.

I can't confirm that lean fuel conditions will cause a spike in the voltage of the secondary ignition system though, I haven't heard of it..... also, like you, I have an electrical engineering background and don't understand it, either. I have seen Old Master's contributions to this forum for the last few years, though, and know that he isn't the type to make stuff up.